Apparatus for setting machine tools



July 15, 1941.

T. DRESCHERQ APPARATUS or; SETTINGIMACHINE TOOLS Filed Dec. 2, 1939 THEODORE B.fDRESHER s PATENT OFFICE APPARATUS FOR SETTING MACHINE TOOLS Theodore B. Drescher, Brighton, N. Y., assignor to Bausch & Lomb Optical Company, Rochester, N. Y., a corporation of New York Application December 2, 1939, Serial No. 307,296

v UNITED STATE the work piece is cut to proper form.

4 Claims. '(01. 29-57) The present invention relates to an apparatus for accurately positioning or checking the position of a forming tool relative to a work piece.

Machine tools such as turret lathes, screw ma-. chines orthe like, are usually set up by crude cut and try methods. The various tools are set intheir approximate positions and a piece is cut. This work piece is then measured and, unless cuts are all correct, the tools are reset. The process is then repeated again and again until These repeated set-ups and cuts not only consume a great deal of time butresult in a considerable waste of material.

It is an object oi the present invention to avoid this laborious and expensive method of setting up and to provide an apparatus by which tools may be positioned accurately relative to the work piece. Another object is to provide an apparatus in which an enlarged image of a tool is projected on a surface carrying an enlarged outline of the finishedwork piece. A further object is to provide an apparatus for checking the contour, size and position of a cutting tool relative to the contour, size and position of the piece to be cut. These and other objects and advantages reside in certain novel features of construction, arrangement and combination of parts as will hereinafter be more fully set forth and pointed out in the appended claims.

In the drawing:

Fig. 1 is an elevation of a turret lathe having my new tool positioning apparatus.-

Flgs. 2 and 3- are elevations of the screen showing difl'erent tool positions.

Fig. 4 is a plan view of the lathe turret.

Fig. 5 is a side elevation of the projection system.

Fig. 6 is a diagrammatic view of the projection optical system. 4

- The positioning and checking of the tools of a turret lathe constitute an important application of my invention and it is. in connection with such a machine that my invention is illustrated. The actual structure of the turret lathe forms no part of the invention and hence the construction of the lathe is not shown in detail.

The lathe illustrated in the drawing consists of a table or support lll'upon which is mounted the lathe bed The lathe head I2 is mounted at one end of the bed II and the turret I3 is ro- Y tatably mounted on a carriage H which moves toward and from the head l2 along the bed The usual control levers l5 and I6 regulate the speed and direction-of rotation, and a hand wheel I1 serves to position the carriage l4 and turret I I3 is hexagonal and each face has an opening is for receiving a tool holder 20. Various tools 2|, 22 and 23 for performing various operations are adjustably secured in the tool holders 20 by bolts 24.

In operation, the carriage It moves along the bed H to bring a tool, for example,-the drill 2|, into cutting relation to' a work piece in the chuck It. When this tool has completed its work, the carriage ll moves back away from the workpiece, the turret l3 revolves to bring another tool, for example, the drill 22, into operative position and the carriage 'Magainmoves forward toward the work piece. The construction and operation of these turret lathes is well known to persons skilled in the art.

According to the present invention a projection apparatus is suitably mounted above the locus of the work piece. This apparatus may be mounted on a bracket 25 secured to the lathe head |2 by bolts 26 or it maybe mounted independently of the lathe. One projection system which is satisfactory in practicing my invention is that illustrated in U. S. Patent 1,934,582issued November '1, 1933, to E. Bausch et al. for Projection apparatus. This projectionsystem consists of an objective lens 2|, a right-angle roof prism 28, two plane reflectors]! and 30 and a All of these elements, I

projection screen 3|. prefer to mount in a suitable housing 32 and the housing 32 may be secured to the bracket 25 or other support. In this projection system, the lens 21 is pr ferably of a predetermined focal I length and the optical distance from the lens 21 to the projectionscreen 3| is preferably predetermined and fixed. When these conditions are met, an image formed by the lens 21 Jon the screen 3| will have a fixed and predetermined magnification. r

A drawing or template 33 of the piece to be cut is 'made'on a scale equal to the magnification of the projection system. Thus, if the magnification of the projection system is like, the drawing I or template is made on a like scale. This drawing ortemplate 33 is then suitably secured on the screen 3|. In .the example shown in the drawing, the work piece is to be cut with a large central hole 35 and a smaller hole 34 extending" into the piece from the bottom of the hole 35; The end of the piece is to be squared on around the hole 35 and the outside of the piece cut back held in a chuck-- to a shoulder 36. It is-to be understood that- 'this particular shape is given merely by way of example and that my invention can be used for any desired shape of finished piece. I

The projector is mounted so that the position of the screen 3i and drawing or template a is conjugate to the locus of the work piece.

means for supporting a cutting tool in cutting relation with the work piece, the checking of the tool being made prior tosupporting the tool for a cutting operation and with the tool in a 5 position corresponding to that which it would assume-with respect to a work piece at the completion of its cuttingoperation, said apparatus comprising an objective lens, means for supporting the objective lens adjacent said tool and with its object plane substantially at the locus of a work piece, a template, and means for supporting the template in the focal plane of the lens conjugate to the locus of said work piece, saidtemplate being shaped in the form to be cut on said work piece and being of a size equal to When the images ii, 22' and 21' correspond to the drawing or template a as shown in Figs. 1, 2 and 3, the tools 2|, 22 and are in proper position to cut the proper surfaces on the work piece. Thus the first piece cut is absolutely accurate, no measuring or resetting is necessary and spoiled test pieces are eliminated.

As illustrated, the template or drawing 33 has the form and size of the finished piece but it can, of course, take other forms. Two scales 'at check the contour, size and location of the tool.

In order to form a clear and distinct image, it will probably be necessary to use a suitable source of light 31. This light source 31 may beabove or below the tool and causes a sharp image of the tool to be formed on the screen.

From the foregoing, it will'be apparent that I am able to attain the objects of my invention and provide a new and improved apparatus for checking the size, contour and position of machine tools. While I have illustrated my invention in connection with a turret lathe, obviously it is applicable to a variety of machines and to abrading as well as cutting tools. Various modi thesize of said work piece times the magnification of'the objective lens.

3. In a cutting machine of the type having means for supporting a work piece, means for supporting a cutting tool and means for moving '25 prising, a projection screen adjacent to the maright angles on the screen would be sufiicient to the cutting tool into cutting relation with the work piece, an apparatusfor checking the size, position and contour of the tool prior to supporting a workpiece for a cutting operation com chine. means carried by said screen for representing in profileat a predetermined magnification the size. and the contour to which the work piece is to be cut, an objective lens for forming an image of said tool on said screen in a position with respect to said profile which corresponds to the position assumed by the tool with respect to a work piece carried by the supporting means therefor at the completion of a cutting opera- 35 tion, said lens forming said imageat the predo the lens,-the supporting means for the tool being fications of structure can also be made without departing from the spirit of my invention or the scope of the appended claims.

' I claim: v v

1. In a cutting machine of the type'having means for supporting awork piece, means for supporting a cutting tool and means for moving the cutting tool into cutting relation with the work piece, an apparatus for checking the size, position and contour of the tool prior to supporting a work piece for a cutting operation, com- I prising, a projection screen adjacent to the machine, means carried by said screen for representing in profile' at a predetermined magnification the size and the contour to which the work piece is to be cut, an objective lens for forming an image of said tool on said screen in a position to the position assumed by the tool'with respect to a work piece carried by the supporting means therefor at the completion of a cutting operation, said lens forming said image at the predetermined magnification of the profile, and means for supporting the objective lens between the tool and the screen.-

also provided with adjustable means whereby a supported tool may be repositioned in the support to cause its image to coincide with said profile. v

4, An apparatus to. assist in the setting of a cutting tool of a lathe in a position corresponding to that necessarily assumed by said tool at the completion of its cutting operation in making a desired cut, the lathe having a work holder and a movable tool holder adjustably supporting a cutting tool, said apparatus comprising a projection system having an objective lens, a projection screen in fixed spaced relation to the lens, optical means between said lens and screen" for inverting and reverting an image formed by said lens, means for supporting the means for securing the drawing on the screen, with respect to said profile which corresponds said drawing being made to a scale equal to the 5 tool is formed on the screen adjacent, said draw- 2. An apparatus for checking the size, position and contour of a cutting tool of a machine of the type having a support for a work piece and setting of the.

ing of the work piece and in a position which corresponds to that actually assumed by the tool with respect to the work piece on the completion oi its cutting operation for the particular tool in its holder.

THEODORE l3.- ;1DRESCHER. 

